2868 Federal Register / Vol. 78, No. 9 / Monday, January 14, 2013 / Proposed Rules 

can be used as a way to determine the 

annoyance qualities of a sound. The values 

from a one-third-octave analysis can also be 

easily presented in tabular form (Table 1), 

while those from a full-spectrum cannot. 

TABLE 8—EXAMPLE OF ONE-THIRD-OCTAVE DATA IN TABULAR FORM: SUMMARY OF AMBIENT LEVELS DURING ICE 

MEASUREMENTS, A-WEIGHTED LEVEL, DB(A) 

1⁄3 octave band center frequency, Hz 

Linear average 

(1⁄3 octave 

band) 

Min (overall 

A-weighted) 

Max (overall 

A-weighted) 

Min (1⁄3 octave 

band) 

Max (1⁄3

octave band) 

100 to 20k ............................................................................ 49.6 46.1 53.4 45.3 54.7 

100 ....................................................................................... 34.6 30.7 34.1 30.7 38.4 

125 ....................................................................................... 35.5 32.4 36.8 32.4 42.1 

160 ....................................................................................... 36.1 32.1 37.9 32.0 41.5 

200 ....................................................................................... 36.9 32.7 37.9 32.7 41.2 

250 ....................................................................................... 36.5 33.9 38.1 33.1 40.7 

315 ....................................................................................... 36.5 32.5 37.6 32.1 41.5 

400 ....................................................................................... 36.0 31.9 38.1 31.8 39.7 

500 ....................................................................................... 36.7 33.6 39.8 33.1 41.1 

630 ....................................................................................... 38.2 34.4 41.7 34.0 42.2 

800 ....................................................................................... 40.2 36.0 46.1 35.8 46.1 

1k ......................................................................................... 41.1 36.4 46.4 36.4 46.4 

12.5k .................................................................................... 40.0 35.3 45.1 35.3 45.1 

16k ....................................................................................... 37.6 32.9 43.1 32.9 43.1 

2k ......................................................................................... 34.7 30.3 37.8 30.3 37.8 

2.5k ...................................................................................... 34.5 32.8 35.4 30.8 42.1 

3.15k .................................................................................... 35.5 36.9 37.1 30.0 39.6 

4k ......................................................................................... 34.0 33.0 34.3 28.3 40.2 

5k ......................................................................................... 29.0 25.0 29.8 24.3 32.8 

6.3k ...................................................................................... 25.7 22.3 26.9 19.7 31.7 

8k ......................................................................................... 20.2 16.6 22.4 14.1 24.2 

10k ....................................................................................... 14.4 10.3 17.3 7.6 18.3 

12.5k .................................................................................... 8.9 5.0 11.7 3.2 13.0 

16k ....................................................................................... 3.1 0.7 5.6 ¥0.8 8.7 

20k ....................................................................................... ¥1.9 ¥3.1 ¥0.4 ¥3.5 2.0 

Summary 

The acoustic science described above was 

intended to provide novices enough 

knowledge to understand the data and 

discussions put forth in the NPRM. Sound is 

a form of energy that is created when a 

medium vibrates, creating pressure variations 

(compressions and rarefactions of molecules) 

within a medium (such as air) which creates 

a pattern called a wave. Sound pressure over 

time creates peaks and valleys which make 

up the wavelength. The difference in acoustic 

pressure from the ambient pressure (no 

contraction of the medium) to the peak or 

valley of a wavelength is called the 

amplitude; the higher the amplitude, the 

louder the sound. The period of a wave is the 

time it takes for a cycle (a peak and a valley) 

to complete; a longer period indicates a lower 

pitch. The frequency of a sound is the 

number of complete wave cycles that pass by 

a given point in space every second; the 

higher the frequency, the higher the pitch. 

The wavelength, amplitude, period and 

frequency are physical attributes of a sound 

wave that affect the human perception of 

loudness, pitch and timbre. These 

perceptions can be quantified using 

psychoacoustics. Psychoacoustics is the 

study of how humans perceive sound and 

forms the basis for extracting objective data 

from the physical characteristics of acoustic 

pressure (sound). Using the physical 

characteristics and psychoacoustic analysis, a 

sound is usually measured in decibels (dBs) 

within an octave. Octaves can be further 

broken down into one-third octave bands 

which provide more information about the 

spectral content of sound being analyzed. 

After reading this primer, the reader should 

understand what ‘‘sound’’ is, identify its 

different components, and understand how 

humans perceive sound and how each of 

these contributes to measuring sound. 

References 

[1] Christopher L. Morfey, Dictionary of 

Acoustics, Academic Press, 2001. 

[2] ANSI S1.1–1994, Acoustical Terminology, 

American National Standards Institute, 

1994. 

[3] CEI IEC 50(801), International 

Electrotechnical Vocabulary—Chapter 

801: Acoustics and Electroacoustics, 

International Electrotechnical 

Commission, 2nd Edition, 1994. 

[4] ANSI S3.20–1973, Psychoacoustical 

Terminology, American National 

Standards Institute, 1973. 

[5] Brian C. J. Moore, An Introduction to the 

Psychology of Hearing, Academic Press, 

4th Edition, 1997. 

[6] Lawrence E. Kinsler, Austin R. Frey, Alan 

B. Coppens, and James V. Sanders, 

Fundamentals of Acoustics, John Wiley 

and Sons, 3rd Edition, 1982. 

[7] E. Zwicker and H. Fastl, Psychoacoustics: 

Facts and Models, Springer, 2nd Edition, 

1999. 

[8] Leo L. Beranek, Acoustical Measurements, 

American Institute of Physics, 1988. 

[9] Garay-Vega, Lisandra; Hastings, Aaron; 

Pollard, John K.; Zuschlag, Michael; and 

Stearns, Mary D., Quieter Cars and the 

Safety of Blind Pedestrians: Phase 2, 

John A. Volpe National Transportation 

Systems Center, DOT HS 811 496 

October 2011, available at http:// 

www.nhtsa.gov/DOT/NHTSA/NVS/ 

Crash%20Avoidance/ 

Technical%20Publications/2011/ 

811496.pdf. 

Issued in Washington, DC on January 7, 

2013, under authority delegated in 49 CFR 

1.95. 

Christopher J. Bonanti, 

Associate Administrator for Rulemaking. 

[FR Doc. 2013–00359 Filed 1–9–13; 4:15 pm] 

BILLING CODE 4910–59–P 

DEPARTMENT OF TRANSPORTATION 

National Highway Traffic Safety 

Administration 

49 CFR Parts 571 and 585 

[Docket No. NHTSA–2011–0100] 

Draft Environmental Assessment for 

Rulemaking To Establish Minimum 

Sound Requirements for Hybrid and 

Electric Vehicles 

AGENCY: National Highway Traffic 

Safety Administration (NHTSA), 

Department of Transportation (DOT). 

ACTION: Notice of availability. 


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Federal Register / Vol. 78, No. 9 / Monday, January 14, 2013 / Proposed Rules 2869 

SUMMARY: NHTSA is announcing the 

availability of a Draft Environmental 

Assessment (EA) to evaluate the 

potential environmental impacts of a 

proposed rule establishing a Federal 

Motor Vehicle Safety Standard (FMVSS) 

setting minimum sound requirements 

for hybrid and electric vehicles. 

DATES: Comments must be received on 

or before March 15, 2013. 

ADDRESSES: You may submit comments 

on the EA to the docket number 

identified in the heading of this 

document using any of the following 

methods: 

• Federal eRulemaking Portal: go to 

http://www.regulations.gov. Follow the 

online instructions for submitting 

comments. 

• Mail: Docket Management Facility, 

M–30, U.S. Department of 

Transportation, West Building, Ground 

Floor, Rm. W12–140, 1200 New Jersey 

Avenue SE., Washington, DC 20590. 

• Hand Delivery or Courier: West 

Building Ground Floor, Room W12–140, 

1200 New Jersey Avenue SE., between 

9 a.m. and 5 p.m. Eastern Time, Monday 

through Friday, except Federal holidays. 

• Fax: (202) 493–2251. 

Regardless of how you submit your 

comments, you should mention the 

docket number of this document. 

You may call the Docket at 202–366– 

9324. 

Instructions: For detailed instructions 

on submitting comments and additional 

information on the rulemaking process, 

see the Public Participation heading of 

the Supplementary Information section 

of this document. Note that all 

comments received will be posted 

without change to http:// 

www.regulations.gov, including any 

personal information provided. 

FOR FURTHER INFORMATION CONTACT: For 

non-legal issues, Ms. Gayle Dalrymple, 

Office of Crash Avoidance Standards, 

National Highway Traffic Safety 

Administration, NVS–112, 1200 New 

Jersey Avenue SE., Washington, DC 

20590. Telephone: 202–366–5559; fax: 

202–493–2990. 

For legal issues, Mr. Russell Krupen, 

Office of the Chief Counsel, National 

Highway Traffic Safety Administration, 

NCC–113, 1200 New Jersey Avenue SE., 

Washington, DC 20590. Telephone: 

202–366–1834; fax: 202–366–3820. 

SUPPLEMENTARY INFORMATION: Pursuant 

to the National Environmental Policy 

Act, NHTSA has prepared a Draft EA 

analyzing the potential environmental 

impacts of the agency’s proposed action 

to establish minimum sound 

requirements for hybrid and electric 

vehicles. The Draft EA is being issued 

together with the agency’s Notice of 

Proposed Rulemaking for FMVSS 

No.141, Minimum Sound Requirements 

for Hybrid and Electric Vehicles. The 

proposal would require hybrid and 

electric passenger cars, light trucks, 

medium and heavy duty trucks and 

buses, low speed vehicles, and 

motorcycles to meet certain minimum 

sound requirements and would apply to 

electric vehicles and to those hybrid 

vehicles that are capable of propulsion 

in any forward or reverse gear without 

operation of the vehicle’s internal 

combustion engine. 

On July 12, 2011, the agency 

published a Notice of Intent to Prepare 

an Environmental Assessment, which 

sought comment on the scope of the 

environmental analysis, the significant 

issues to be analyzed, and the nature of 

the analysis to be conducted. NHTSA 

received comments to the Notice of 

Intent from 35 individuals and 

organizations. NHTSA developed the 

alternatives analyzed in the Draft EA 

based on the comments received and 

further research and analysis conducted 

by the agency. 

NHTSA invites interested parties to 

comment on the Draft EA by following 

the instructions under ADDRESSES

above. The Draft EA is available on the 

agency’s Web site at http:// 

www.nhtsa.gov or on the public docket 

at http://www.regulations.gov (Docket 

No. NHTSA–2011–0100). 

Issued on: January 7, 2013. 

Christopher J. Bonanti, 

Associate Administrator for Rulemaking. 

[FR Doc. 2013–00361 Filed 1–9–13; 4:15 pm] 

BILLING CODE 4910–59–P 


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